NEVER MIND = Uggh found a 2017 loophole that a 2nd home must be self-propelled RV. Can't find where to delete the post. Sorry
I saw this article today and thought of all those who DIY solar panels and even add solar options from ETI's build sheet. It's a brief reminder that you MIGHT qualify for tax rebate/credit (in US). As always, with this type of stuff = YMMV, seek professional advice